A041430 Numerators of continued fraction convergents to sqrt(231).

15, 76, 2295, 11551, 348825, 1755676, 53019105, 266851201, 8058555135, 40559626876, 1224847361415, 6164796433951, 186168740379945, 937008498333676, 28296423690390225, 142419126950284801, 4300870232198934255

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..200

Index entries for linear recurrences with constant coefficients, signature (0,152,0,-1).

Formula

a(n) = 152*a(n-2)-a(n-4). G.f.: -(x^3 - 15*x^2 - 76*x - 15)/(x^4-152*x^2+1). [Colin Barker, Jul 15 2012]

Mathematica

CoefficientList[Series[- (x^3 - 15 x^2 - 76 x - 15)/(x^4 - 152 x^2 + 1), {x, 0, 20}], x] (* Vincenzo Librandi, Oct 27 2013 *)
LinearRecurrence[{0, 152, 0, -1}, {15, 76, 2295, 11551}, 20] (* Harvey P. Dale, Mar 06 2023 *)

Crossrefs

Cf. A041431.

Sequence in context: A212241 A000477 A302376 * A156941 A205440 A051423

Adjacent sequences: A041427 A041428 A041429 * A041431 A041432 A041433

Keyword

nonn,cofr,frac,easy

Author

N. J. A. Sloane.

Status

approved